Abstract

Final morphological polarization of neurons, with the development of a distinct axon and of several dendrites, is preceded by phases of non-polarized architecture. The earliest of these phases is that of the round neuron arising from the last mitosis. A second non polarized stage corresponds to the bipolar neuron, with two morphologically identical neurites. Both phases have their distinctive relevance in the establishment of neuronal polarity. During the round cell stage a decision is made as to where from the cell periphery a first neurite will form, thus creating the first sign of asymmetry. At the bipolar stage a decision is made as to which of the two neurites becomes the axon in neurons polarizing in vitro and the leading edge in neurons in situ. In this study we analysed cytoskeletal and membrane dynamics in cells at these two “pre-polarity” stages. By mean of time lapse imaging in dissociated hippocampal neurons and ex vivo cortical slices we show that both stages are characterized by polarized intracellular arrangements, however with distinct temporal hierarchies: polarized actin dynamics marks the site of first polarization in round cells, whereas polarized membrane dynamics precedes asymmetric growth in the bipolar stage.

Pavan Vedula and Anna Kashina propose a new concept, the actin code, which encompasses the regulation of the essential functions of mammalian actins at the nucleotide level, rather than at the level of amino acids.

“To me, there are no real boundaries between chemistry, biology, physics and maths.”

Tony leads a group at the Mechanobiology Institute in Singapore, focusing on dissecting the structure–function relationship that underlies protein complexes that are involved in cell migration and adhesion. He shares his thoughts on why you don’t necessarily have to choose between the different branches of science that you find fascinating.

We also feature interviews with first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Check out our recent First Person interview with Julia Abitbol.

The second in our series of cell dynamics meetings now turns to organelles. This May 2019 meeting in Lisbon, Portugal, aims to bring together scientists studying the interface between organelles and the cytoskeleton at different scales and perspectives using a range of model systems. Find out more and register your interest here.

We are currently seeking proposals for four Workshops to be held in 2020. Do you have an idea for a Workshop? Please let us know and you could be one of our 2020 Workshop organisers. You focus on the science, we focus on the logistics. We are particularly keen to receive proposals from postdocs. Deadline date for applications is 25 May 2018.

Meet the preLighters! In the latest interview with our preLights community, the preLights team caught up with James Gagnon, Assistant Professor at the University of Utah, to talk about his research, how science can be made more open, his enthusiasm for the preLights project and the fun sides of being a junior PI.

Alexander García Ponce investigated how hematopoietic stem cell (HSC) cross the vascular wall and reach the bone marrow as part of his PhD project, with an aim to improving the outcome of HSC transplantation for individuals with leukaemia. A Travelling Fellowship from JCS allowed Alexander to advance his research at the Sanquin Blood Bank in The Netherlands. Read more on his story here.

Where could your research take you? Join Alexander and apply for the next round of Travelling Fellowships from JCS by 25 May 2018.